Adjustable mercury dispenser

ABSTRACT

A dental amalgam dispenser having a reservoir and a cap connected thereto having a transverse passage provided with a plunger slidable longitudinally therein. The plunger has a mercury-receiving space adapted to communicate respectively with inlet and discharge ports in said cap when moved longitudinally in said passage, and means operable relative to said plunger to vary the volume of said space to provide measured quantities of mercury of different desired amounts.

United States Patent [19] Welsh ADJUSTABLE MERCURY DISPENSER [75] Inventor: Richard E. Welsh, Milford, Del.

[73] Assignee: Dentsply Research & Development,

Milford, Del.

[22] Filed: Feb. 28, 1973 [21] Appl. No.: 336,678

[52] [1.8. CI. 222/43, 222/307 [51] Int. Cl. B67d 5/22, GOlf l H16 [58] Field of Search 222/23, 41, 43, 288, 305,

[56] References Cited UNlTED STATES PATENTS 5/l942 Angell 222/308 8/1952 Smoot 222/43 X June 4, 1974 Sampson 222/309 Hanson 222/288 Primary Examiner-Robert B. Reeves Assistant ExaminerFrancis J. Bartuska [57] ABSTRACT 6 Claims, 9 Drawing Figures 1 ADJUSTABLE MERCURY DISPENSER BACKGROUND OF THE INVENTION The present invention pertains to a mercury dispenser of the type used by dentists and dental technicians for purposes of measuring relatively precise amounts of mercury for mixture with metal powder, such as various types of silver alloys, in order to produce a desired quantity of amalgam for use in restorative dentistry comprising the filling of prepared cavities in human teeth. Due to the fact that prepared cavities are of many different sizes relative to different teeth, it is obvious that amalgam mixtures of comparable different amounts are desirable in order to prevent unnecessary waste of material.

In order to conserve time and also for convenience, it has been customary for many years to provide mercury reservoirs in the form of small bottles in which, for example, the mercury may initially be sold. Such reservoir is mounted in leak-proof manner within a cap or head having dispensing mechanism which, for many years, has comprised either a longitudinally reciprocable or rotatable plunger or cylindrical member in which a recess or space is provided into which mercury may flow from the reservoir until the space is filled, and then, by either moving the plunger longitudinally or rotating it, the measured quantity of mercury is discharged from the cap or head through a suitable discharge port. The discharged mercury is received within a small mixing receptacle, if manual mixing with metal powder is desired, or the mercury is discharged into a capsule in which the metal to be mixed with the mercury is included in the capsule and the same is mounted in a vibratory-type machine, in common use in many dental offices, for purposes of intimately mixing the mercury and metal powder to form the amalgam.

Measuring small quantities of variable desired amounts of mercury has presented certain problems heretofore. One expedient used to solve the problem has been to furnish a plurality of plungers or movable members respectively having spaces or recesses therein of different sizes for purposes of receiving different amounts of mercury and effecting discharge thereof from the dispenser. This expedient, however, has necessitated the removal of a previously used plunger from the dispenser and substituting one having a different size of mercury-receiving space therein when a dif-, ferent amount of mercury from that capable of being measured by the preceding plunger was desired. Such an arrangement obviously not only is a nuisance but necessitates storing a plurality of plungers having different sizes of mercury-receiving spaces therein.

Other attempts to solve problems of this type comprise the subject matter of several prior patents. One of these is U.S. Pat. No. 2,081,544, to Crivig, dated May 25, I937. Providing a mercury-receiving space or recess in a slidable plunger is accomplished by a threadably adjustable rod being movable tovarious distances within said space. Such an arrangement, however, is limited in adjustability substantially to one complete revolution of the threaded member and thus, does not provide any substantial range of latitude in regard to adjusting the size of the mercury-receiving space.

Another patent dealing with the problem is U.S. Pat. No. 3,670,928, to Hanson. issued June 20, I972. Essentially, the patent is directed to a powder metering device for loading ammunition and in which a plunger has an annular space of variable capacity determined by visual indications used in regard to adjusting the capacity of the space and also including an adjustable stop member. A plurality of concentric indicating rings are formed on the plunger to assist in determining the capacity of the space, but no identity is included on such rings, whereby determining a desired capacity for the powder-receiving space in the plunger is difficult and capable of a mistaken identity being used with re gard to the indicating means.

The difficulties with the existing adjustable dispensing devices referred to above are obviated by the present invention, the principal objectives of which are as follows:

SUMMARY OF THE INVENTION It is the principal object of the present invention to provide an adjustable dental mercury dispenser, including a reservoir and a head connected thereto, the head having a passage extending transversely therethrough for slidable reception of a plunger having a space of adjustable size therein which receives mercury from the reservoir and discharges the same through a discharge port .in the head, the principal contribution of the invention comprising means to adjust the volume or capacity of the mercury-receiving space, said means including an element having multiple-level surface means thereon and an abutment in a cooperating element which is adapted to selectively engage a desired surface of said multiple-level means to quickly and accurately adjust and maintain the volume of the mercuryreceiving space.

It is another object of the invention to provide visual indicating means corresponding to the various surface levels of said multiple-level surface means to quickly and accurately indicate a desired capacity of said mercury-receiving space.

It is a further object of the invention to associate the.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side elevation of an exemplary mercury dispenser embodying the principles of the present invention, a portion thereof being illustrated in vertical section.

FIG. 2 is a fragmentary side elevation of the left-hand side of the dispenser shown in FIG. 1, details thereof being illustrated on a larger scale than in FIG. 1.

FIG. 3 is a fragmentary vertical elevation of measuring details illustrated in FIG. 1, but shown on a substantially larger scale in FIG. 3.

FIG. 4 is an end view of one of the elements of the measuring mechanism.

FIG. 5 is a longitudinal sectional view of the elements shown in FIG. 4 as seen on the line 5-5 thereof.

FIG. 6 is a fragmentary vertical sectional view showing details of the adjustment mechanism by which adjustment of the mercury dispenser is accomplished.

FIG. 7 is a face view of the inner end of an element of the adjusting mechanism shown in FIG. 6, as seen on the line 7-7 thereof.

FIG. 8 is a perspective view of the element shown in FIG. 7 in association with a phantom-type illustration of another element of the mechanism shown in FIG. 6 with which the element of FIG. 7 is associated, said elements being shown in separated relationship in FIG. 8.

FIG. 9 is an extended, diagrammatic view illustrating various levels of the adjusting element shown in FIG. 7.

DETAILED DESCRIPTION Referring to FIG. 1, an adjustable mercury dispenser which embodies the principles of the present invention is shown in vertical elevation, partly in section. Said view illustrates a bottle-like reservoir 10, which holds a supply of mercury for dental use. It is customary in the dental profession for reservoirs of this type to comprise small glass bottles within which the mercury is sold. The normal top or neck 12 of the bottle is provided with threads-which are complementary to mating threads on the interior of the cap or head 14, which is constructed to contain the principles of the present invention.

The cap or head 14 may be molded from any suitable material, such as thermo-setting synthetic resin or any other suitable material, resin, or otherwise, which is not reactive in any way with mercury. The head 14 is provided with a passage 16 which extends transversely between opposite sides of-the head 14. For purposes of minimizing wear, as well as facilitating manufacture thereof, the transverse passage 16 is lined with a metal tube 18, whereby for practical purposes; it may be considered that the passage l6 comprises the inner surface of the tube 18.

The head 14 is provided with an inletport 20, which, at one end, communicates with the passage 16 and, at the opposite end, opens into the interior of the socket 22, which'is internally threaded and provided in the head to receive the neck 12 of the bottle reservoir 10, whereby communication is established between the interior of the bottle reservoir and the passage 16. Preferably, the socket 22 also contains a gasket 24 against which the terminal end of the neck 12 of the bottle reservoir 10 abuts to renderthe engagement leak-proof. Longitudinally spaced from the inlet port at its juncture with the transverse passage 16 is a discharge port 26, which, at its inner end, communicates with the transverse passage 16 and the opposite end communicates with atmosphere for discharge of a mea sured quantity of mercury, achieved by means to be described, which falls by gravity into a mixing receptacle or capsule, due to the fact that during such measuring and discharge operation, the dispenser is held in what may be considered an inverted position as shown in FIGS. 1 and 2.

Measuring and discharge of mercury is accomplished by means of a member 28, which comprises a plunger that is slidably movable within the transverse passage 16. Said plunger is composite in nature. Also, in crosssectional shape, it is complementary to the crosssectional shape of the transverse passage 16, which, preferably, is circular. However, the invention is not to be restricted to a circular shape since other geometric cross-sectional configurations are possible to be used with perhaps minimum revision of the details described hereinafter. In the preferred construction, the plunger 28 has a shank end 30 of uniform diameter which terminates at its outer end in a knurled button 32 of greater diameter than that of the shank 30. The opposite end of the shank comprises two sections 34 and 36, which respectively and successively are of smaller diameters than that of the shank end 30. The diameter of section 36 is slightly smaller than that of section 34, for

purposes to be described.

, A sleeve 38 is longitudinally slidable upon the reduced diameter sections 34 and 36, the interior diameter of the sleeve being complementary to the outer diameter of section 34. The surface ofthe shoulder 40 on the shank 30 and the preferably flat end 42 of sleeve 38 define between them an annular mercury-receiving space 44 which is adjustable in volume by means of movement of the sleeve 38 longitudinally relative to the reduced diameter section 34. Such movement is accomplished by means described hereinafter and the reversible direction of such movment is indicated by the movement-indicating double-headed arrow shown in FIG. 3. Also, the interior diameter of sleeve 38 which is adjacent the end 42 thereof has a smaller diameter surface portion 46, which is complementary to the outer diameter of the section 36 of reduced diameter on theshank 30. Such arrangement provides an elongated interior cylindrical space 48 which receives a compression spring 50, which at one end abuts the shoulder 52 on section 34of shank 30 and the opposite end abuts annular shoulder 54 at one end of the surface portion 46 on the interior of sleeve 38, asshown best in FIG. 3. This arrangement insures accurate positioning of the end 42 of sleeve 38 withrespect to the shoulder 40 on shank 30 after the sleeve 38 has been suitably adjusted, by means described hereinafter, to provide a mercury-receiving space 44 of desired volume.

For purposes of effecting the adjustable positioning of sleeve 38 relative to shoulder 40 on shank 30, a cupshaped knob 56 is secured to the outer end of sleeve 38 as shown in FIGS. 3 and 6. If desired, astop ring 58 may be-suitably fixed to the sleeve 38 for abutment, for example, with one end of the tube 18, such as when the sleeve 38 is adjusted to provide the mercury-receiving space 44 of smallest volume. The interior of the knob 56 receives a multiple-level surface member 60. If desired, both the cup-shaped knob 56 and member'60 may be formed from any suitable material such as metal or synthetic resin and be manufactured therefrom by molding or any other suitable process. Also, on the interior of cup-shaped knob 56 is an abutment 62 which, for example, may be molded integrally with the inner surface of knob 56 or, if desired, said abutment may be in the form of a pin extending radially inwardly from the sidewall of the knob 56. The abutment is for purposes of abutting one of the multiple levels 64, 66, 68, 70, 72, or 74, which are formed on the inner end 76 of the member 60, such as by molding, milling, or any other suitable procedure. Each of said levels is a different distance from the outer end 78 of the member Particularly as viewed in FIG. 8, it will be seen that the various levels 64-74 are spaced inwardly from the inner end 76 of member so as to actually comprise the bottoms of recesses within which the abutment 68 is selectively disposable to effect a desired positioning of the end 42 of sleeve 38 relative to the shoulder 40 on shank 30, due to the fact that the member 60 is nonadjustably connected to the outer end of section 36 of shank 30 which actually comprises a rod. Especially when the member 60 is formed from plastic, a metal insert 80 having a threaded bore for engagement with a complementary threaded end 82 on section 36 of shank 30 which comprises said aforementioned shaft. Such threaded arrangement permits assembly of the entire plunger member 28 and the positioning means comprising the multiple-level surface member 60 and abutment 62, which are enclosed within the cup-shaped knob 56. This assembly also includes a compression coiled spring 82, which surrounds the outer portion of the shank 30 and extends between the knurled button 32 and the outer end of the tube 18 which is nearest said button, as illustrated particularly in FIG. 1. The function of said spring is to normally maintain the mercury-receiving space 44 of the plunger member 28 in association with the inlet port 20 so as to receive mercury from the reservoir 10. Upon moving the plunger member 28 towardthe right, as viewed in FIG. 1, the

shank 30 closes the port 20 while the mercury within the space 44 is being moved into registry with thedisthe plunger member 28 a short distance toward the left,-

as viewed in FIG. 1. This preferably is done when the reservoir 10 and the head 14 are in the upright position which is opposite that shown in FIG. 1. Holding the button 32 in the aforementioned adjusted position by a finger or thumb, the knob 56 then is moved toward the head 14 a sufficient distance to remove the abutment 62 within the knob from its reception in one of the recesses formed in the inner end of multiple-level surface member 60, until the inner end 76 thereof is cleared. Holding the button 32 against rotation correspondingly holds the multiple-level surface member 60 against rotation, whereupon the knob 56 may be rotated in the desired direction in order to dispose one of the multiple-level surfaces 64-74 in axial alignment with the abutment 62. Under such conditions, the spring 48 is compressed, as well as the spring 82. When the desired level surface of member 60 has been moved in opposition to the abutment 62, the knob 56 is released which permits the spring 50 to permit movement of the knob 56 and, correspondingly, sleeve 38 to the left, as viewed in FIGS. 1, 3 and 6, until the abutment 62 bottoms against a selected surface level of the multiple-levels 64-74, and thereby establishes a desired length of the annular mercury-receiving space 44, which provides a desired volume into which a measured quantity of mercury will fall by gravity, when the dispenser is maintained in the position shown in FIG. 1, following the release of the button 32, which permits spring 82 to restore the space 44 into registry with inlet port 20.

As can be seen particularly from FIG. 6, the positioning means for sleeve 38 is relatively short in comparison with the diameter. The diameter is such as to permit easy manipulation manually. To afford ready visual appreciation of the relative depths of the multiple-level surfaces 64-74, attention is directed to FIG. 9 in which a theoretical, diagrammatic expanded view of the periphery of member is shown, said illustration primarily being exemplary rather than restrictive. In order to provide the desired different quantities of mercury to be dispensed by the device, however, the annular space 44 resulting from positioning of the abutment 62 respectively in engagement with each of the surfaces 64-74, the distances of said surfaces from the outer end 78 of member 60 have been carefully calculated to provide such desired volumes.

To facilitate quick and accurate positioning of the abutment 62 relative to one of the surfaces 6474, the outer end 78 of member 60 is provided with a plurality of indicia 84 respectively indicating a suitable range of volumes or amounts respectively produced when the abutment 62 bottoms against one of the multiple-level surfaces 64-74. The relative position of the abutment 62 with respect to said multiple-level surfaces is indicated by an additional indication 86 for relative positioning with respect to one of the indicia 84. The indi cation 86 is formed on the outer rim of the cup-shaped 'knob 56 so that the same is readily alignable with one of the indicia 84. Also, it is obvious that the knob 56 may be rotated in either desired position, as indicated by the double-headed arrow shown on knob 56 in FIG. 2

From the foregoing, it will be seen that the present invention provides an adjustable mercury dispenser of the type primarily designed for dental use and having readily adjustable means by which different amounts of mercury may be quickly and accurately dispensed from a reservoir therefor. The adjustment of the positioning means which determines the desired amount of mercury is readily manipulatable manually, and adesired setting is effected by relative positioning of an indicating means with a selected indicia on another member of the positioning means, all of which are readily visible from one end of the plunger. The mechanism is relatively fool-proof in operation and spring return means insure positioning of the plunger in mercury-receiving relationship with respect to the reservoir, whereupon movement of the plunger against said spring carries the mercury-receiving space on the plunger to a discharge port in the head of the dispenser.

While the invention has been described and illustrated in its several preferred embodiments, it should be understood that the invention is not to be limited to the precise details herein illustrated and described since the same may be carried out in other ways falling within the scope of the invention as illustrated and described.

I claim:

1. An adjustable dental mercury dispenser adapted to dispense accurately-measured quantities of mercury and comprising in combination, a reservoir for a supply of mercury, a head connected to one end of said reservoir and having a passage extending transversely therethrough and communicating with inlet and discharge ports arranged at spaced locations in said passage and opening respectively into said reservoir and the exterior of said head, a compound plunger having a first section complementary in cross-section to said passage and closely slidable therein and a second section of smaller diameter extending coaxially from one end of said first section and forming an annular shoulder therewith comprising one wall of an annular mercurymeasuring space, a sleeve closely slidable on said second section and the outer diameter being complementary in cross-section to said passage and slidable therein, one end of said sleeve which is nearest said shoulder comprising the opposite wall of said annular mercury-measuring space, and positioning means connected to the opposite end of said sleeve and said second section of said plunger and operable axially and rotatably relative to the axis of said plunger to position said one end of said sleeve adjustably relative to said shoulder to provide an annular mercury-receiving space of a selected volume, said positioning means including cooperating multi-level surface means and an abutment selectively engageable therewith and respectively carried by said sleeve and second section of said plunger to position said walls of said space selectively a precise distance apart to measure a desired quantity of mercury in said space.

2. The dispenser according to claim 1 in which said multiple-level surface means comprises a substantially cylindrical element connected to said second section of said plunger member and having on one end a plurality of circumferentially spaced surfaces respectively spaced different distances from the other end of said element, and said abutment being connected to said sleeve.

3. The dispenser according to claim 2 further including spring means operable between said sleeve and said second section of said plunger and operable to yieldably position said abutment in engagement with a selected surface of said cylindrical element.

4. The dispenser according to claim 2 further includ ing a cup-like member interconnected to said sleeve and having said abutment fixed to the interior thereof, and said cylindrical element being disposed substantially within said cup member when engaging said abutment.

5. The dispenser according to claim 4 having cooperating indicating means on the outer ends of said cylindrical member and cup member.

6. The dispenser according to claim 4 in which said cup-like member projects axially from one end of said plunger and the other end of said plunger has a fingerengageable member thereon, and a compressible coil spring surrounding said plunger between said head and said finger-engageable member and operable normally to hold said mercury-receiving space on said plunger in registry with said inlet port in said head. 

1. An adjustable dental mercury dispenser adapted to dispense accurately-measured quantities of mercury and comprising in combination, a reservoir for a supply of mercury, a head connected to one end of said reservoir and having a passage extending transversely therethrough and communicating with inlet and discharge ports arranged at spaced locations in said passage and opening respectively into said reservoir and the exterior of said head, a compound plunger having a first section complementary in cross-section to said passage and closely slidable therein and a second section of smaller diameter extending coaxially from one end of said first section and forming an annular shoulder therewith comprising one wall of an annular mercury-measuring space, a sleeve closely slidable on said second section and the outer diameter being complementary in cross-section to said passage and slidable therein, one end of said sleeve which is nearest said shoulder comprising the opposite wall of said annular mercury-measuring space, and positioning means connected to the opposite end of said sleeve and said second section of said plunger and operable axially and rotatably relative to the axis of said plunger to position said one end of said sleeve adjustably relative to said shoulder to provide an annular mercury-receiving space of a selected volume, said positioning means including cooperating multi-level surface means and an abutment selectively engageable therewith and respectively carried by said sleeve and second section of said plunger to position said walls of said space selectively a precise distance apart to measure a desired quantity of mercury in said space.
 2. The dispenser according to claim 1 in which said multiple-level surface means comprises a substantially cylindrical element connected to said second section of said plunger member and having on one end a plurality of circumferentially spaced surfaces respectively spaced different distances from the other end of said element, and said abutment being connected to said sleeve.
 3. The dispenser according to claim 2 further including spring means operable between said sleeve and said second section of said plunger and operable to yieldably position said abutment in engagement with a selected surface of said cylindrical element.
 4. The dispenser according to claim 2 further including a cup-like member interconnected to said sleeve and having said abutment fixed to the interior thereof, and said cylindrical element being disposed substantially within said cup member when engaging said abutment.
 5. The dispenser according to claim 4 having cooperating indicating means on the outer ends of said cylindrical member and cup member.
 6. The dispenser according to claim 4 in which said cup-like member projects axially from one end of said plunger and the other end of said plunger has a finger-engageable member thereon, and a compressible coil spring surrounding said plunger between said head and said finger-engageable member and operable normally to hold said mercury-receiving space on said plunger in registry with said inlet port in said head. 